Vets are warning southern farmers about a resurgence of the killer disease Salmonella Brandenburg in sheep flocks in Southland and Otago. The disease, which strikes in winter, can take a high toll of ewes and the lambs they may be carrying.

It can also spread to people who come into contact with infected stock.

Winton vet Kim Rutherford says more than a quarter of the farmers surveyed by her practice reported Salmonella Brandenburg in their flocks last lambing season, a big increase compared with previous years. Rutherford says that in some flocks up to half the sheep that caught the disease have died.

Meanwhil,e Dunedin District Medical Officer of Health Dr John Holmes has raised concerns about the growing percentage of children catching the disease. He says the number of human cases reported has halved in the past eight years but children made up almost half of the 58 cases reported last year.